Question

我有一个数据库。我在sqlcommand中从数据库中获取两个值，但我面临的一个问题是如何从reader（）中的表中获取adminstatus ..

我的代码

protected void signin_Click(object sender, EventArgs e)
    {

    string connectionString = ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString;

    using (SqlConnection conn = new SqlConnection(connectionString))
    using (SqlCommand comm = new SqlCommand("SELECT password,adminstatus FROM usertable WHERE userid = @username", conn))
    {
        comm.Parameters.AddWithValue("@username", logintext.Text);

        conn.Open();

        using (SqlDataReader reader = comm.ExecuteReader())
        {
            if (reader.Read())
            {
                string password = reader.GetString(0);
                //int st =Convert.ToInt32(reader.GetString(1));
                //int st = reader.GetInt32(0);
                if (password == logpasstext.Text)
                {
                    Session["userid"] = logintext.Text;
                   // iframestyle.Attributes["src"] = "userpage.aspx";
                    iframestyle.Attributes["src"] = "userpage.aspx";
                    logdiv.Attributes["style"] = "display:none;";
                }
              /*  else if (password == logpasstext.Text && st == 1)
                {
                    Session["userid"] = logintext.Text;
                    // iframestyle.Attributes["src"] = "userpage.aspx";
                    iframestyle.Attributes["src"] = "adminpage.aspx";
                    logdiv.Attributes["style"] = "display:none;";
                }*/

                else
                {
                    errorsignin.Visible = true;
                    errorsignin.Text = "INVALID LOGIN";
                    logdiv.Attributes["style"] = "display:block;";
                }
            }
            else
            {
                errorsignin.Visible = true;
                errorsignin.Text = "INVALID LOGIN";
                logdiv.Attributes["style"] = "display:block;";
            }
        }
    }
}

我无法使用阅读器从表中获取adminstatus ...

Answer 1

尝试将string indexer与SQLDataReader一起使用。只需指定要撤消的列名称

 string adminstatus= Convert.ToString(reader["AdminStatus"]); 
// Assuming AdminStatus is a column name

Answer 2

string adminStatus = reader.GetString(1)

其中＆＃34; 1＆＃34;是查询中字段的位置

或更好：

string adminStatus = reader.GetString(reader.GetOrdinal("adminstatus"))

reader.GetOrdinal("adminstatus")返回查询中字段的位置

你必须更换＆＃34; GetString＆＃34;使用与数据类型对应的方法（例如，GetInt32或GetFloat或GetBoolean）

http://msdn.microsoft.com/en-us/library/system.data.sqlclient.sqldatareader(v=vs.110).aspx

Answer 3

您可以使用reader.GetOrdinal(ColumnName)来避免幻数。

然后我去

//if adminstatus is a SQL string like the other field
reader.GetString(reader.GetOrdinal("adminstatus")); // returns string

//if adminstatus is for example a SQL bit 
reader.GetBoolean(reader.GetOrdinal("adminstatus")); // returns bool

如何从asp.net中的数据库中检索值？

3 个答案: